Skin cracking and postharvest water loss of Jalapeño chilli

• Fruit developed early in the season had a high incidence of cracking.
• Crop load had a smaller influence on cracking incidence.
• Cracking increases the water vapour permeance of the skin by a factor of 3.
• Water is lost equally from skin and stem (calyx and pedicel) in non-cracked fruit.
• Temperature and humidity control are the most important influences on weight loss.

Water loss affects quality and limits marketable life of fresh produce. Chillies and peppers are susceptible to water loss that occurs through the calyx, pedicel, and skin surface. Flux through the skin is influenced by cuticular cracking, a common physical defect for Jalapeño. A high incidence of cracking was found.to be caused by harvest date, with those fruit developed early in the season having the highest incidence. Although cracks developed corky suberisation, fluorescence microscopy showed the central portion of the cracks was unsuberised. The water vapour permeance (mol s−1 m−2 Pa−1) of cracked Jalapeño was approximately three times higher than non-cracked fruit. However, the calyx and pedicel of Jalapeño were found to exhibit higher water vapour permeance than fruit skin for both cracked and non-cracked Jalapeño. After accounting for the surface area of each structure, the majority of water is lost via the fruit skin in cracked fruit, while water is equally lost from fruit skin and stem area (calyx and pedicel) in non-cracked fruit. A model was developed to predict Jalapeño shelf life (assuming that 5% water loss resulted in shrivel development) and used to conduct a sensitivity analysis on factors that influence time to shrivel development. Fruit weight and P′H2OP′H2O differences in the population had little effect on time to shrivel development. Cracking does reduce time to shrivel significantly but storage temperature and RH have such a big impact that water loss in Jalapeño remains best controlled through good cool chain management and packaging.